Apparatus for producing bass sounds in electric musical instruments wherein contrabass voice can be obtained by special switch and circuit



Feb. 16, 1965 MICHIO KONDO 3,170,020

APPARATUS FOR PRODUCING BASS sounns IN ELECTRIC MUSICAL INSTRUMENTS WHEREIN CONTRABASS VOICE CAN BE OBTAINED BY SPECIAL swI'rcH AND cmcun Filed Oct. :5. 1960 Fig; 14

wait mam MM v QM; -93 W United States Patent 3,170,020 APPARATUS FOR PRODUCING BASS SOUNDS IN ELECTRIC MUSKCAL INSTRUMENTS WHEREIN CONTRABASS VQICE CAN BE OBTAINED BY SPECIAL SWITCH AND CIRCUIT Michio Kondo, Hamamatsu-shi, Japan, assignor to Nrhon Galtlri Seizo Kahushilri Kaisha, Hamamatsu-shi, Japan Filed Get. 3, 1960, Ser. No. 60,114 Claims priority, application Japan, Apr. 6, 1960, 20,143/60 1 Claim. (Cl. 84-126) My invention relates to an apparatus for producing bass sounds in electric musical instruments.

The object of this invention is to provide a novel circuit arrangement which can produce decaying sounds which are like contrabass vocal sounds.

My invention may be more clearly understood by referring to the accompanying drawing in which:

FIG. 1 shows a decay characteristic curve of a pedal sound decaying system embodying this invention;

FIG. 2 shows a connection diagram of a pedal sound decaying system embodying this invention.

Referring now to FIG. 2 of the accompanying drawing, the apparatus comprises input terminals 1, 1, 1", 1

for pedal sound signals, an output terminal 2 for the pedal sound signals, blocking condensers C G a condenser C of a time constant circuit which serves to determine the length of decay, a resistor R of said time constant circuit which serves to vary the length of decay, resistors R R R and R a transistor T and pedal key switches (SW1, SW (SW2, SW which are arranged in such a manner that by depressing the pedal 3, the switch SW1 is closed and the switch SW is opened, and so on. The switch SW is adjusted to open earlier than closing of the switch SW1 and when switch SW is opened, transistor T is gradually cut off by the resistor R and the condenser C Adjustment of each of the other pairs of the switches is the same as that of the pair of switches SW1 and SW The switches SW1, SW2 are connected in parallel, while switches SW SW are connected in series.

In FIG. 1, point C represents a point at which the switch SW operates and point 0. represents a point at which the switch SW1 operates. When the switch SW1 operates, the transistor T is gradually cut off, whereby the amplitude T of the signal, output voltage appearing at the terminal 2 decays as shown by the dot and dash line b of FIG. 1 even if the switch SW1 is operated to introduce the pedal signal input into the transistor T Accordingly, according to my invention, it the pedal key switch is operated by a quick motion, the signal output voltage appearing at the terminal 2 will begin to decay from the moment at which the switch is depressed, so that a human ear can feel decaying sound similar to a contrabass voice.

While the invention has been explainedby describing a particular embodiment thereof, it will be apparent that 3,170,020 Patented Feb. 16, 1965 improvements and modifications may be made without departing from the scope of the invention as defined in the appended claim.

What I claim is:

In an electrical musical instrument, an arrangement to produce contrabass-like decaying sounds, comprising in combination;

a plurality of input terminals to which are applied sound signals and a plurality of first switch means, each responsive to a pedal, one side of each of said first switch means being connected to one of said input terminals, said first switch means being normally open;

a like plurality of second switch means, normally closed, all in series, each of said second switch means corresponding to one of said first switch means including a first, power source lead line, to the first in the series of said second switch means;

mechanical means between each one of said first and second switch means to open one of said second switch means when one of said first switch means are closed, adjusted so that said second switch means will open earlier than the closing of said first switch means;

a decaying circuit between said first and second switch means including a first condenser connected by a common terminal with each of said first switch means, a transistor with base, emitter, collector electrodes, the base of which is coupled to said first condenser, base bias resistor means, a collector load resistor, an emitter the last in the series of resistor connected in series between said emitter and said second switch means, a second condenser between the collector electrode and the output side of the arrangement, a second, power source lead line connected to said collector load resistor and base bias resistor means; and,

a timing resistor and timing condenser both in parallel with each other between the second power source lead line and said emitter, the time constant between said resistor and condenser being so set as to gradually cut oif said transistor so that the sound signal applied to the decaying circuit through the closing of one of said first switch means is lead out from, said second condenser as a decaying sound signal.

References Cited by the Examiner UNITED STATES PATENTS 2,483,823 10/49 George 84-1.26 2,848,919 8/58 Hanert 84-126 2,924,784 2/60 Peterson 84-126 2,953,056 9/60 Hanert 841.26

ARTHUR GAUSS, Primary Examiner.

CARL W. ROBINSON, Examiner. 

